After neonatal banding of either the pulmonary artery (PA) or the aorta neonatal sheep were allowed to grow for one year, producing either left ventricular hypertrophy (LVH) or right ventricular hypertrophy (RVH). Along with a group of control sheep, the experimental sheep underwent a standardized warm ischemic protocol. Intramyocardial pH as monitored by a fiberoptic probe was allowed to fall to 6.8 by cross clamping the aorta during full cardiopulmonary bypass. Left and right ventricular function were measured before and after bypass, and degree of recovery measured by Starling curve creation.